How can I use dotted property name for Localization Resource names in a CSHS?

It seems that if I use a Localization Resource within a Client Side Human Service (CSHS) I am not supposed to use '.' (dot) in a localization key. At the same time it works fine with Heritage Human Service.

The definition is the following:

It is referenced in the CSHS via Client Side Script:

//tw.local.variable1 = tw.resource.localizationRes1.btn.accept;

But it throws the following error:

tw.resource.localizationRes1.btn is undefined

How can I use dotted property name for Localization Resource names in a CSHS?